How does phenotypic plasticity happen?



  • Instantaneous / instinctual responses

  • Gene expression responses

    • DNA -> RNA
  • Epigenetic responses

    • whet
    • study of how your behaviors and environment can cause changes that affect the way your genes work

How does phenotypic plasticity happen?



  • Instantaneous / instinctual responses

How does phenotypic plasticity happen?



  • Instantaneous / instinctual responses

How does phenotypic plasticity happen?



  • Gene expression responses

How does phenotypic plasticity happen?



  • Epigenetic responses

Different types of genetic changes


Changes to DNA sequence underlie adaptation


Changes to DNA sequence underlie plasticity


Changes to DNA sequence underlie plasticity


Changes to DNA sequence underlie plasticity



Traditionally it was thought that changes to the sequence of DNA were heritable while changes to the expression patterns of DNA were not


That made it easy to define adaptation as “heritable genetic change” and plasticity as “non-genetic”


But those lines are becoming blurred as we learn about mechanisms (like histone modification) that can make gene expression changes heritable

The problem of concepts…


The adjust response



Adjust: non-genetic shifts in organismal traits in different environments (phenotypic plasticity)


The adjust response happens at the level of the individual and happens within a single generation


The adapt response happens at the level of the population and happens across generations

Case Study: Limpopo National Park






Village communities used the region before the establishment of Limpopo National Park


After the park’s establishment, village communities live within the park buffer zone


The buffer zone is an important area for wildlife

People, Parks, and Climate Change



Strategies Dealing with Drought before the National Park


  • Small plots in multiple areas
  • Sharing plots
  • Seeding at every rainfall
  • Temporary migration
  • Crop mixing

People, Parks, and Climate Change



Strategies Dealing with Drought before the National Park


WILDLIFE: As drought intensifies, elephants compensate by increasing usage of areas nearest the river, including crop fields


HUMAN: Village communities respond by using fencing and altering cropping practices

People, Parks, and Climate Change


Meet the Data: Shifts with global warming


Meet the Data: Shifts with global warming



What shifts (in space and time) do we see most commonly for organisms with global warming?



  • Geographic shifts toward the poles
  • Geographic shifts up in elevation
  • Seasonal shifts earlier in the year

Phenotypic plasticity in development


Example from insects: As ecotherms, temperature matters a lot for insect survival, development, dispersal, etc.
Insect life histories are very tied to environmental factors

Phenotypic plasticity in development


  • For example, a major effect of global warming on insects is to speed up developmental rates
    • can lead to faster maturity


In the UK >70% of butterfly species studies have earlier “first flight”


First flight is predicted to occur 2-10 days earlier for every 1°C

Phenotypic plasticity in development


  • For example, a major effect of global warming on insects is to speed up developmental rates
    • can lead to more generations per year



increase of temperatures by 2°C is predicted to allow some aphid species to produce an additional 4–5generations per year.

Phenotypic plasticity in development



Temperature-induced advancement in development is common and relates to a broader pattern…


Phenological changes: changes in periodic biological phenomena (like flowering, breeding, migration, etc.)

Phenotypic plasticity in development



2003 meta-analyses found an advancement of an average of 2.3 days per decade
Remarkably consistent across groups (and that was 20 years ago!!!)

Phenotypic plasticity in development



With global warming we expect many temperature dependent processes to occur earlier in the year


Even a few days matters…


Phenological mismatch: When interacting species are no longer temporally or spatially aligned (we will return to this in Chap 9)

Friday Open Discussion: Can Humans Adjust to Global Change?



  • Journal Club message: Humans have high adatptive capacity..
    • what about short term change?


  • What evidence exists? Past, present and/or future
    • can we acclimate to …..
    • what traits are plastic (or not)


  • Be prepared to discuss what you found as well as your opinion on if it is possible


  • Submit an article/finding on Brightspace for participation